Autoinducer-2 controls virulence of Salmonella enterica serovar Typhimurium

Authors: JESUDHASAN, P - TEXAS A&M UNIVERSITY; CEPEDA, M - TEXAS A&M UNIVERSITY; WIDMER, K - TEXAS A&M UNIVERSITY; Dowd, Scot; SONI, K - TEXAS A&M UNIVERSITY; Hume, Michael; Zhu, James; PILLAI, S - TEXAS A&M UNIVERSITY

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 8/28/2007
Publication Date: 8/27/2007
Citation: Jesudhasan, P.R., Cepeda, M.L., Widmer, K., Dowd, S.E., Soni, K.A., Hume, M.E., Zhu, J., Pillai, S.D. 2007. Autoinducer-2 controls virulence of Salmonella enterica serovar Typhimurium [abstract]. American Society for Microbiology Cell to Cell Communication in Bacteria Abstracts, October 7-10, 2007, Austin, Texas. No. 108A.

Interpretive Summary:

Technical Abstract: Bacterial communication via quorum sensing (QS) has been reported to be important in the production of virulence factors, antibiotic sensitivity, and biofilm development. Three QS systems, known as the autoinducer (AI) - AI-1, AI-2, and AI-3 systems, have been identified previously in the foodborne pathogen Salmonella Typhimurium. High-density oligonucleotide microarrays for the Salmonella Typhimurium genome were used to investigate global gene expression patterns of Salmonella Typhimurium luxS mutant modulated by QS regulon (in vitro synthesized AI-2). In the presence of synthetic AI-2, 708 genes were differentially expressed (350 up-regulated and 358 down-regulated) with P<0.05. Quantitative real time PCR was performed on selected genes to validate the microarray analysis. Although the only known role of AI-2 in Salmonella Typhimurium is the regulation of the lsr operon which helps to internalize AI-2, the microarray analysis reveals that AI-2 also represses virulence genes in Salmonella Typhimurium. Our results suggest that AI-2 could be a master regulator of genes in the pathogenicity island of Salmonella Typhimurium.